This file shows land area flooding at the tract level and county for the state of Georgia. It also pulls out tract locations of high flooding as well as their subsequent counties. It then multiplies tract social vulnerability indicator percentiles by flooding proportion to create a flooding-vulnerability, which is also interactively mapped. Finally, a comparison is drawn between flooded FEMA community lifelines and area flooded by county.
The datasets are the National 100-Year flood layer (2018), CDC SVI indicators (2018), and Re-Public’s database of flooded community lifelines (all from 2018).
These estimates show that as a result of a 100-Year flood, Georgia is 14.79% flooded by land area (which likely includes wetland areas as well). Coastal counties face the brunt of flooding (up to 60% of land area flooded), though the southeastern corner of Georgia as well as various inland tracts also have high risk.
The datasets include 1966 tracts, 1960 of which are mapped. Of those 1966, 117 have null values for flood data. We assume that in the case of missing flood data, the % tract flooded is 0, though these values are graphed as NA at this time.
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## ℹ Use `spec()` for the full column specifications.The following plot shows tract-level land area flooding.
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## Need '+proj=longlat +datum=WGS84'These following table outlines a list of tracts with flooding close to or above 50%.
## Simple feature collection with 70 features and 2 fields
## geometry type: MULTIPOLYGON
## dimension: XY
## bbox: xmin: -84.98855 ymin: 30.56852 xmax: -80.83973 ymax: 34.26293
## geographic CRS: NAD83
## # A tibble: 70 x 3
## LOCATION CensusTractSubmerg… geometry
## <chr> <dbl> <MULTIPOLYGON [°]>
## 1 Census Tract 9900… 100 (((-81.194 31.57093, -81.18948 31.568…
## 2 Census Tract 9900… 100 (((-81.26668 31.50631, -81.26252 31.5…
## 3 Census Tract 106.… 97.8 (((-84.17031 31.5493, -84.16405 31.55…
## 4 Census Tract 111.… 96.5 (((-80.97446 31.98381, -80.97252 31.9…
## 5 Census Tract 9, G… 94.6 (((-81.49668 31.14877, -81.4847 31.15…
## 6 Census Tract 115,… 89.4 (((-81.24293 31.89407, -81.24142 31.8…
## 7 Census Tract 1.01… 89.1 (((-81.4026 31.13732, -81.39988 31.13…
## 8 Census Tract 111.… 87.0 (((-80.93591 31.96253, -80.93071 31.9…
## 9 Census Tract 111.… 86.8 (((-81.0481 32.0316, -81.04648 32.033…
## 10 Census Tract 8, G… 85.0 (((-81.52685 31.16402, -81.52151 31.1…
## # … with 60 more rowsThis dataset includes the flooded area by county, calculated by summing tracts by county.
## `summarise()` ungrouping output (override with `.groups` argument)## # A tibble: 159 x 2
## COUNTYFP county_flooded
## <chr> <dbl>
## 1 051 60.2
## 2 179 58.2
## 3 191 57.6
## 4 029 56.6
## 5 127 52.4
## 6 299 52.3
## 7 183 51.3
## 8 049 49.6
## 9 065 49.2
## 10 039 45.5
## # … with 149 more rowsThe interactive plot below includes county names and subsequent flooding.
## Warning: sf layer has inconsistent datum (+proj=longlat +datum=NAD83 +no_defs).
## Need '+proj=longlat +datum=WGS84'Looking specifically at our 7 counties of analysis: Chatham: 60.169% flooded Liberty: 58.159% flooded McIntosh: 57.641% flooded Stewart: 8.796% flooded Colquitt: 15.611% flooded Rabun: 4.794% flooded Whitfield: 10.099% flooded
Social Vulnerability Indicators and Flooding
For every tract, we calculated a combined social vulnerability-flooding score by multiplying the vulnerability percentile (ranked at the state level) with the tract flooding. This was done for the overall vulnerability percentile, socioeconomic vulnerability percentile, household composition vulnerability percentile, language isolation vulnerability percentile, and housing structure vulnerability percentile.
Below is a table that includes the top 10 most “vulnerable” tracts based on overall flooding and SVI rankings.
This graphic shows the scores from the overall vulnerability percentile.
This graphic shows the scores from the socioeconomic vulnerability percentile.
This graphic shows the scores from the household composition vulnerability percentile.
This graphic shows the scores from the language isolation vulnerability percentile.